Compact polarized illuminators using reflective polarizers

• Main Authors: Yun, Zhisheng, McDowell, Erin A, Ouderkirk, Andrew J
• Format: Patent
• Language: English
• Published: 14.02.2023
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; BLASTING; CINEMATOGRAPHY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; ELECTROGRAPHY; FREQUENCY-CHANGING; HEATING; HOLOGRAPHY; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATINGELEMENTS; LIGHTING; MECHANICAL ENGINEERING; NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHOTOGRAPHY; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; WEAPONS

Projection systems and components thereof are described that are well suited to miniaturization. These systems and components may use one or more of the following features: a folded optical path, as in a reflective cavity or a beamsplitter; an illumination beam that is converging at the place where it impinges upon the spatial light modulator; a beamsplitter that uses opposed prisms of substantially different sizes; a beamsplitter whose obliquely disposed partial reflector defines a first rectangular reference space, and where at least a portion of the light source or at least a portion of the projector lens is disposed within such first rectangular reference space; a system in which a ratio of areas of the first rectangular reference space and a second rectangular reference space is within a specified range, where the second rectangular reference space is just large enough to encompass the optical components of the projector; a system in which the projector lens is small compared to the spatial light modulator.